1. Field of the Invention
The present invention relates to a technology concerning an automotive headlamp, for example, an automotive headlamp capable of switching light distribution patterns.
2. Description of the Related Art
Traditionally, an automotive headlamp, which has a projector type lamp unit projecting and distributing reflected light forward from a reflector by a projection lens, is known (JP 2010-9766 A). This automotive headlamp is capable of switching light distribution patterns by arranging a movable light shielding shade for light distribution control between the reflector and the projection lens. In this automotive headlamp, the light shielding shade is moved by a motor.
The automotive headlamp described above moves the shade until it abuts against a stopper by driving the motor when a high beam light distribution pattern is formed. The automotive headlamp includes a spring to bring back the shade to a low beam light distribution pattern forming position when the motor is not driven.
However, it is necessary for the automotive headlamp described above to continue supplying power to the motor with the shade abutting against the stopper in order to hold the shade at a high beam light distribution pattern forming position. Therefore, it was found that the motor vibrates and an abnormal noise (high frequency noise) is generated when the power is supplied to the motor when the rotation of the motor is stopped. The generated abnormal noise continues until the motor is turned off.